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High performance self-powered photodetector based on van der Waals heterojunction
Cong Yan1, Kun Yang1, Hao Zhang1
1Key Laboratory for Wide-Band Gap Semiconductor Materials and Devices of Education, The School of Microelectronics, Xidian University, Xi'an 710071, People's Republic of China.
Nanotechnology
|October 18, 2023
Summary
Researchers developed a novel self-powered photodetector using In2Se3/WSe2/ReS2 van der Waals heterojunctions. This device significantly enhances photocurrent and response speed, offering a promising solution for low-power, high-performance optoelectronics.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Nanotechnology
Background:
- Self-powered photodetectors are crucial for low-power applications, but achieving high responsivity is challenging.
- Two-dimensional (2D) van der Waals heterojunctions offer excellent optical and electrical properties for advanced photodetector designs.
Purpose of the Study:
- To fabricate and characterize a self-powered photodetector based on an In2Se3/WSe2/ReS2 van der Waals heterojunction.
- To investigate the role of the ReS2 layer and back-gate voltage in enhancing photodetector performance.
Main Methods:
- Fabrication of a three-material van der Waals heterojunction using In2Se3, WSe2, and ReS2.
- Characterization of the photodetector's performance, including responsivity, photocurrent, and response time.
- Application of a negative back-gate voltage to modulate the built-in electric field.
Main Results:
- The In2Se3/WSe2/ReS2 heterojunction photodetector exhibited a 17-fold increase in responsivity (438 mA W-1) compared to the In2Se3/WSe2 device.
- A significant enhancement in self-powered current (1.1 nA) and a 250% faster response time were observed.
- The addition of the ReS2 layer improved light absorption and carrier generation efficiency.
Conclusions:
- The fabricated In2Se3/WSe2/ReS2 heterojunction photodetector demonstrates superior performance due to enhanced built-in electric fields and wider depletion zones.
- This work provides a new technological pathway for developing high-responsivity, low-power, and high-speed self-powered photodetectors.
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